You know I have played with fans and ex changers and baseboards .. I have 152-160f degree water going to 60,000 btus exchanger
and about 1200 cfm on exchanger temp drop is 10-13 degrees at -21f keeps the house 76f 28x48 house what part am I missing that everyone need that water temp at 175 f I also have a 100,000 btu exchanger with a 500cfm fan heating shop 32x32 keeps what ever I set it pull as much as 19 degrees off water . my boiler does same thing top of tank can be from 165-185f when im burning slabs
you just -10 degrees and thats what lower output temp is in the house .. Baseboards you cant get a enough heat to them there for slow small room heating in my book . ( bedrooms bathrooms etc.) I think ductwork and fan air flow is a bigger deal . 150f air coming off a exchanger when water 175f will take your breath away stinking nasty hot . don't like fan noise get quiter fan there's nice ones out there . Last thought check your in ground lines and see how much heat there robing .
this my findings with heatmor 400 and 200 . and older houses 1976 and 1991
heat550
looked on the website ozark there pulling water out the of top of the tanks this give you wild temps . mixing would be totally different then my setup.